On Wed, May 3, 2017 at 7:05 AM, Benoît Thébaudeau <benoit@xxxxxxxxxxx> wrote: > The SDHCI_QUIRK_NO_MULTIBLOCK quirk was used as a workaround for the > ENGcm07207 erratum. However, it caused excruciatingly slow SD transfers > (300 kB/s on average), and this erratum actually does not imply that > multiple-block transfers are not supported, so this was overkill. > > The suggested workaround for this erratum is to set SYSCTL.RSTA, but the > simple DAT line software reset (which resets the DMA circuit among > others) triggered by sdhci_finish_data() in case of errors seems to be > sufficient. Indeed, generating errors in a controlled manner on i.MX25 > using the FEVT register right in the middle of read data transfers > without this quirk shows that nothing is written to the buffer by the > eSDHC past CMD12, and no extra Auto CMD12 is sent with AC12EN set, so > the data transfers on AHB are properly aborted. For write data > transfers, neither extra data nor extra Auto CMD12 is sent, as expected. > Moreover, after intensive stress tests on i.MX25, removing > SDHCI_QUIRK_NO_MULTIBLOCK seems to be safe. > > Signed-off-by: Benoît Thébaudeau <benoit@xxxxxxxxxxx> Reviewed-by: Fabio Estevam <fabio.estevam@xxxxxxx> -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
